MERCEDES-BENZ has doubled the number of available variants in its R-class range, with a long-wheelbase version of its all-wheel-drive people mover to hit Australian showrooms in March, priced at $108,900.

Mercedes claims this is $11,977 less than a 2010 model with the same level of equipment would have cost.

The longer, more powerful R350 CDI closely follows Mercedes’ R-class facelift in which it culled much of the range – from six variants to one – last November.

The length of the LWB version has been increased by 235mm to 5157mm and total luggage capacity is increased by 414 litres.

The R350 CDI has a modified version of the 3.0-litre turbo-diesel V6 from the existing R-Class that produces 195kW and 620Nm, compared to the 140kW and 440Nm available in SWB guise.

The sprint from 0-100km/h is completed in a respectable 7.7 seconds, down from 9.8 seconds in the SWB. The seven-speed automatic from the R300 CDI remains standard.

The enhanced output of the turbo-diesel comes courtesy of a raft of software and mechanical alterations, resulting in the R350 CDI being more fuel efficient than the SWB R300 CDI, despite being both bigger and faster.

Combined fuel consumption is listed as 8.5l/100km, down from 9.3l/100km in the SWB model. CO2 emissions from the R350 CDI are 223g/km.

Sales of Mercedes’ premium people carrier rose 13.5 per cent in 2010, to 194 units. That said, the segment-straddling car – part SUV, part people mover – has struggled to carve out a niche for itself in Australia since it went on sale in its original guise in 2006.